Test 2 part I Flashcards
the somatic and autonomic nervous systems are functional components of _______________ neurons of the _______________ nervous system
motor; peripheral
__________________ is a functional part of the peripheral nervous system that controls involuntary responses (like CO, flow distribution, and digestion)
autonomic nervous system
what are the 2 divisions of the autonomic nervous system
sympathetic and parasympathetic divisions
the autonomic nervous system is primarily concerned with control and integration of _________________ functions
visceral
which component of the peripheral nervous system is responsible for voluntary motor control?
somatic nervous system
the central nervous system functions through use of ____________________
negative feedback loops
T/F: there are new theories emerging on vagus related immune function as a part of the autonomic nervous system
true
negative feedback generally promotes _______________, while positive feedback promotes _____________________
stability; increased fluctuation of output
positive feedback leads to instability via __________________, ________________, or ___________________
exponential growth; oscillation; chaotic behavior
sympathetic nerves leave the CNS through the _____________________ and _______________ spinal nerves, thus is called ______________________
thoracic; lumbar; thoraco-lumbar
the parasympathetic nerves leave the CNS through ________________ and ______________spinal nerves, thus is called ____________________
cranial nerves; sacral; craniosacral
what cranial nerves do parasympathetic nerves leave the CNS through?
III (oculomotor), VII (facial), IX (glossopharyngeal), X (vagus)
(3,7,9,&10)
sympathetic nerves travel via ________________________ preganglionic fibers and then to _____________________ postganglionic fibers
short; long
parasympathetic nerves travel via _____________________ preganglionic fibers and then to __________________ postganglionic fibers
long; short
T/F: some preganglionic fibers of the sympathetic nervous system, terminate in ganglia located outside the organs innervated
false; some parasympathetic fibers do this
what ganglia located outside of the organs innervated do some parasympathetic preganglionic fibers terminate in
- ciliary
- pterygopalatine
- submandibular
- otic
- pelvic
____________________ is sometimes considered a 3rd division of the CNS
enteric nervous system (ENS)
______________________ is a highly organized collection of neurons located in the walls of the GI system that goes from the esophagus to the distal colon
enteric nervous system (ENS)
the enteric nervous system is involved in _______________ and _______________ activities of the gut
motor; sensory
what plexi are included in the enteric nervous system (ENS)
plexus of auerbach (myenteric plexus) and plexus of meissner (submucous plexus)
input to the enteric nervous system is received from what fibers?
sympathetic, parasympathetic, and fibers in the wall of the gut
what is the function of the enteric nervous system
to provide synchronization of impulses that ensure forward propulsion of the gut
which has faster neurotransmitter effects the autonomic or the somatic nervous system
somatic
acetylcholine is a _______________________ on the chemistry molecular level, which means it is __________________ and does not cross the _______________
quaternary ammonium ester; lipid insoluble; blood brain barrier
acetylcholine is synthesized inside the neuron from ____________ + __________ in a reaction controlled by ______________________
choline; acetyl CoA; Choline-acetyl transferase
acetyl coA, a component in the synthesis of acetylcholine is synthesized where?
mitochondria
Acetylcholine in presynaptic vesicles in motor nerve endings are released in the synaptic cleft in ________________
quanta
Ach release is dependent on ________________
calcium
what are the other names for acetylcholinesterase
true cholinesterase
specific cholinesterase
each molecule of acetylcholinesterase degrades ______________ molecules of Ach per second
25,000
T/F: Ach must be synthesized constantly
true; it is not recycled or re-used
when Ach is broken down by acetylcholinesterase, _________________ is recycled to the motor nerve terminal and used to resynthesize Ach
choline
what is the neurotransmitter released from cholinergic fibers?
acetylcholine
what are examples of cholinergic efferent fibers?
- somatic motor nerves
- preganglionic sympathetic fibers
- preganglionic parasympathetic fibers
- post-ganglionic sympathetic sweat glands
- post-ganglionic parasympathetic fibers
almost all efferent nerve fibers leaving the CNS are __________; meaning they release ___________________.
cholinergic; Ach
Ach is hydrolyzed in < _____________ ms by acetylcholinesterase
15
Adrenal medullary cells are stimulated by _______________ to release a mixture of ______________ and __________ into the vasculature
Ach; norepinephrine; epinephrine
what are the 5 key features of neurotransmitter function, which provides potential targets for drugs
- synthesis - can interrupt synthesis of Ach/NE
- storage - can manipulate vesicle formation
- release - trigger/block negative feedback
- termination of action - inhibit negative feedback/acetylcholinesterase
- receptor effects - agonist/antagonist
what are the steps of cholinergic signal transmission?
- influx of Ca via voltage gated calcium channels increase intracellular calcium
- calcium signals the fusion of vesicles (containing Ach) to fuse with the presynaptic membrane
- pores open releasing Ach into the synaptic cleft
- Ach stimulates cholinergic receptors (M / N) on the postsynaptic membrane
- Ach-E hydrolyzes Ach into choline and acetic acid –> choline reabsorbed into presynaptic membrane
if Ach in the synaptic cleft stimulates a muscarinic receptor on the presynaptic membrane, this will cause what?
negative feedback, inhibiting the release of more Ach into the synaptic cleft from the presynaptic membrane
if norepinephrine activates a Beta-1 receptor on the presynaptic membrane, this will cause what?
positive feedback increasing the release of norepinephrine into the synaptic cleft
if norepinephrine activates an Alpha-2 receptor on the presynaptic membrane, this will cause what?
negative feedback, inhibiting the release of more NE into the synaptic cleft
how does precedex work to blunt the sympathetic response
activates alpha 2 receptors on the presynaptic membrane inhibiting further release of NE into the synaptic membrane
what are the steps of adrenergic signal transmission
- influx of Ca via voltage gated channels, increases intracellular calcium
- increased intracellular calcium signals the fusion of vesicles with the presynaptic membrane
- release of NE via expulsion from presynaptic membrane
- stimulation of adrenoreceptors on the post-synaptic membrane
- NE diffuses away for metabolism in the plasma or liver; OR norepinephrine transporter takes NE back to the cyoplasm of the presynaptic membrane
what is the primary method used for removal of Norepinephrine from the synaptic membrane
NET takes NE back to cytoplasm of presynaptic membrane
what causes the high blood pressure in chronic cocaine users postoperatively?
cocaine depletes the NET, therefore, NE unable to be inactivated
what are the different cholinergic receptors
muscarinic
nicotinic
cholinergic receptors respond to what?
Ach - both M and N
muscarine - muscarinic receptors
nicotine - nicotinic receptors
what are your adrenergic receptors
alpha 1
alpha 2
beta 1
beta 2
beta 3
dopamine
Where do the majority of parasympathetic preganglionic fibers terminate?
on ganglion cells distributed diffusely or in networks in the walls of the innervated organs.
Which step is the rate limiting step in the biosynthesis of catecholamines?
conversion of tyrosine to dopa
